Japanese Patent Publication No. 5119727 discloses a battery pack disposed in a case so as to provide battery stacks formed integrally by stacking pouch cells in a thickness direction in a plurality of rows in a longitudinal direction of the battery with spaces therebetween.
The battery pack includes cooling air passages extending in a direction perpendicular to a column direction between the adjoining battery stacks.
The cooling air passages are adapted so that cooling air introduced by a cooling air introducer flows.
Further, the cooling air is configured to contact only on electrode tabs connected to positive terminals or negative terminals of the battery, and on portions of the battery where the electrode tabs are disposed.
Since it is not necessary to ensure the cooling air passage where the cooling air flows in the substantially entire periphery of the battery, it is possible to reduce the size of the battery pack according to the structure of the battery pack disclosed in the Publication No. '727.
However, it is clear that the cooling air contacts the battery body positioned in a side where the electrode tabs are disposed, and it is further clear that surroundings of the battery body and the cooling air passage are in relationship that is physically communicating.
Thus, when gas generated inside the battery is leaked from the battery body, for example, the gas is likely to flow into the cooling air passage.
There is a problem that the gas flowing into the cooling air passage may, for example, be discharged out of the battery pack together with the cooling air, or when the cooling air is not flowing, the gas may be discharged from a place where the cooling air is introduced.
Thus, outflow of the gas may become expanded through the cooling air passage, and it can be assumed that a problem may be caused by the expansion of the gas.